During the grinding work of concrete and the like, generation of dust is inevitable, and various methods have been devised so far to prevent scattering of and collect the dust.
Most of them are of the kind in which a cup-shaped cover covering a grinding cup wheel rotationally driven by using an electric tool such as an angle grinder and a vacuum cleaner is connected to a duct provided at a portion of the cover to collect the dust inside the cover using the suction force of the vacuum cleaner.
Among them, the dust collecting cover introduced in Japanese Patent Laid-open Publication No. 2008-049469 employs the method of connecting an angle grinder to an adapter that is joined to a body cover by a plurality of springs, so that the worker can freely move a head part of the angle grinder and therefore perform finer grinding work. Further, a sub-cover provided at a portion of the body cover is also openable/closable utilizing a magnetic force of magnets, so that the dust collecting cover has a structure allowing even the grinding work close to a wall.
However, since various kinds of angle grinders which are used in the actual sites of work widely vary in shape, it is impossible to design the aforesaid adapter to be commonly used for all of the angle grinders.
Accordingly, for versatility, it is necessary to prepare dedicated adapters matching the respective shapes of the angle grinders. However, with the configuration of the above-described dust collecting cover, all of the springs need to be detached using a special tool such as pliers or the like for replacement of the adapter, thus forcing the worker to perform a difficult and complex work.
Furthermore, the above-described sub-cover, which opens/closes utilizing the magnetic force of the magnets, is not always attached to the body cover by an absolute binding force. Therefore, when the surface of a material to be ground is very coarse and has many steps, the worker has to perform the is grinding work paying close attention not to detach the sub-cover during the work.
The other devised dust collecting covers have problems in the structure, usability, and the dust collecting performance as described in Japanese Patent Laid-open Publication No. 2008-049469, and any of them is far from perfect.